Revert "Revert "disabled any item that appears in the list but should…

… not be enabled. This can occur when the list is longer than the list area allows, so the scrollbar appears. If the list height doesn't divide evenly by the list item height, a little sliver of one last item will be visible at the bottom of the list and it can be clicked. This causes an error. I found that disabling the last item solves the problem. I'm not sure if there are other ramifications to this change, such as any need to re-enable list items if the list length changes, etc. ""

This reverts commit 3bb3197.